Oil viscosity demonstration device



Jan. 25, 1955 M; FAINMAN 2,700,223

011. VISCOSITY DEMONSTRATION DEVICE Filed March 27, 1955 24 Fig. 2 F /g. 1

nited States Patent OIL VISCOSITY DEMONSTRATION DEVICE Morton Fainman, Chicago, Ill., assignor to Standard Oil Company, Chicago, 111., a corporation of Indiana Application March 27, 1953, Serial No. 344,953

3 Claims. (Cl. 35-50) This invention relates to a device for demonstrating the effect of temperature on the viscosity of an oil such as a lubricating oil derived from petroleum. More specifically, it relates to such a device of the falling ball in oil type which is provided with certain novel features adapted to eliminate the introduction of air bubbles to the test portion of the device.

It is highly desirable that the public, in general, and lubricating oil dealers in particular be fully acquainted with the change in viscosity undergone by lubricating oils as ambient and operating temperatures vary, the effect these changes have on performance of the oils and the advantage of employing high viscosity index lubricating oils. Without proper knowledge of these factors the necessity for employment of a lower viscosity oil in winter than in summer and vice versa, the economy of purchasing premium high V. I. oils, etc. might not be understood. Damage to lubricated surfaces can and does result from a lack of this knowledge.

It has, of course, been common practice in the art to employ a plurality of narrow diameter glass tubes containing free metal balls and a series of lubricating oils to demonstrate, at room temperature, the difference between oils of varying viscosities such as SAE 10, 20, 30 and 40 grade oils. The present invention has certain objects analogous to such prior art devices. Thus, it is an object to provide a means for visually demonstrating the need for the proper lubricating oil in mechanical apparatus of all kinds, particularly automobiles, during the changing seasons of the year. A further object is to provide a demonstration device ofthe falling-ball-in-oil type, which may beheated or cooled,

embodying appropriate compensating means for expan- 5:

sion and contraction of the oil. 'A particular object is to provide means in such a device for the prevention of air bubbles interfering with the descending ball. and additional objects will become apparent as the following detailed description is read in conjunction with the attached drawings.

In the drawings:

Fig. l is a partially diagrammatic elevation view of a single demonstration device of the present invention.

Fig. 2 depicts an application of the device shown in Fig. 1 wherein three of such devices are employed side by side to demonstrate comparative viscosity changes with changing temperatures.

Referring now to Fig. 1, the demonstration device of the present invention comprises tube 10, preferably of glass, sealed at both ends and filled with oil up to point 11 permitting free space 12 thereabove. Metal ball 13 (or any other suitable object having a specific gravity substantially greater than any liquid to be tested) is disposed in lower chamber 14 of tube and adapted to move easily from one end to the other of that chamber. Constricting neck 15 with conduit 16 therein, which connects chamber 14 with reservoir chamber 17, is positioned in tube 10. Constricting neck 15 is disposed in tube 10 so that irrespective of tube position the entrance to conduit 16 is always immersed in the liquid in reservoir chamber 17. Thus, the possibility of air entering chamber 14 when the device is turned or the oil is cooled is entirely eliminated and the formation of bubbles is prevented because only oil rather than air may be drawn in.

For purposes of illustrating a specific device of the present invention, and not by way of limitation, the total length of tube 10 is 11 inches, the diameter thereof 0.5 inch, the height of constricting neck 15 is 1% inches and These 2,700,228 Patented Jan. 25, 1955 the distance from the base of said neck to the bottom of tube 10 is 8 inches. Inasmuch as it is desirable that tube 10 in its entirety be transparent, glass and preferably a heat resistant glass such as Pyrex, is preferred. However, other transparent materials such as thermally stable plastics available in the market may be employed either for the whole or a part of the device. According to the preferred embodiment of the invention constricting neck 15 is glass and permanently positioned within tube 10 by well known glass equipment manufacturing techniques. One method of making such a device which has been found particularly suitable is to prepare same from three separate pieces of glass, viz. the tube (sealed at the bottom) enclosing chamber 14, neck 15, and the tube enclosing chamber 17. The base of neck 15 is fused to the top of the lower tube and the base of the upper tube is in turn placed over the neck and fused to the top of the lower chamber. All these fusing and joining operations are well known to one skilled in the art and do not, per se, constitute any part of the present invention. After joining these three pieces, oil is introduced to tube 10 until chamber 14 is completely filled and reservoir 17 is filled to a sufiicient height 11 to assure that the entrance to conduit 16 will always be immersed therein. The tube is then evacuated and sealed. The diameter of conduit 16, and particularly the entrance thereto in chamber 17, is not a critical factor and may vary considerably in size. Principal factors in determining its size are (1) that it preferably be sufficiently large to permit easy filling of the lower chamber, yet (2) that it be not so large as to make it difiicult for it to stay immersed in oil when the device is turned, particularly when it is in a horizontal position.

It is not essential, of course, that neck 15 be glass nor that it be permanently positioned within the tube. Thus a conical insert having a base diameter sufficient to be tightly positioned within tube 10 and held there by friction may be employed. An insert of a resinous material such as polyethylene having a certain amount of extensibility is particularly suitable for insertion in a Pyrex test tube or other readily available glass cylinder. The use of polyethylene or other opaque material, however, is less desirable from the standpoint of appearance inasmuch as a glass neck is essentially invisible in the tube. This is because of the similarity of the refractive indices of oil and glass.

The, apparatus shown in Fig. 2 consists of tubes 18, 19 and 20 which..corresponds.to that shown in Fig. l, disposed in a parallel manner, and positioned between top plate 21 and base plate 22. Handle 23 is afiixed to top plate 21. Vertical support rods 24 and 25 serve to align plates 21 and 22 and in combination with nuts 26 and 27 to firmly maintain the three tubes in the manner shown. There are three hemispherical concavities in the top of base plates 22 in which the bases of tubes 18, 19 and 20 are disposed. The other ends of the three tubes are positioned in cylindrical recesses 28 which are affixed to upper plate 21. Plate 21 and cylindrical recesses 28 are placed over the upper ends of tubes 18, 19 and 20 and nuts 27 are positioned on rods 24 and 25 so as to permit a relatively tight fit of the tubes between the upper and lower plates. These rods pass freely through openings in plate 21. Gaskets of rubber, cork, etc. are preferably disposed between the ends of the tubes and recesses in which they are disposed. After positioning upper plate 21 in the desired location, nuts 26 are tightened on upper plate 21 and the apparatus is completely assembled. Rods 24 and 25 are preferably permanently affixed in base plate 22 but may be screwed into the plate or in any other way afiixed thereto.

For the purpose of illustrating the utility of the apparatus shown in Fig. 2, consider a possible demontration to show the advantage of a high V. I. (Viscosity Index), low viscosity oil at low ambient temperatures, e. g. 0 F., over certain other low viscosity oils of substantially lower V. I. SAE 5 and SAE 10 base oils, with no V. I. improver added, are placed in tubes 13 and 20 respectively. Whereas the SAE 5 base oil has a lower viscosity than the SAE 10 oil and is consequently more desirable for low temperature starting, e. g. at 0 E, the higher viscosity of SAE 10 base oil is more satisfactory at operating temperatures because of less tendency to leak from lubricated parts. It is apparent that an optimum low temperature lubricating oil, e. g. an oil useful in winter in the temperate zone, would have the low viscosit-yproperties of an SAE 5 oil and yet be. not so thin at elevated temperatures as to beinefifective and leak, i. e. it should have essentially the properties of SAE' 10 oil at operating temperature.

The oil placed in tube 19 has a V. I. substantially higher than either of the oils in tubes 18 and 20 and at room temperature, e. g. 70 F., its viscosity is about half-way between that of the other two oils.

To perform the demonstration, the apparatus shown in Fig. 2 is grasped by handle 23' and immersed in a low temperature bath, e. g. maintained at F.,. until equi= librium occurs and then inverted to permit the balls within the three tubes to fall. It will be found that the order in which the three balls descend. is considerably changed from that at room temperature. Whereas at room tem perature the ball in the SAE base oil (tube 18) fell fastest, that in tube 19 the slowest and the middle ball at a rate somewhere between the two, at 0 F. the halt in the high V. I. oil in tube 19 falls at approximately the rate of that in the oilin tube 18. This, of course, clearly demonstrates that the viscosity of the high V. I. oil

in tube 19 was aifected far less than that in tube 18 by the reduction in temperature. The ball in tube 20 would, of course, fall at a substantially slower rate than those in either of the other tubes. When the apparatus is immersed in boiling water, on the other hand, until equilibrium is attained and is then inverted in the same manner, the balls in tubes 19 and 20, i. e. in the high V. I. oil and the SAE base oil, fall at approximately the same rate. Thus, demonstrating that the high V. 1. oil once again undergoes the least change in viscosity and thatwhereas it has a viscosity at 0 F. equal to the best low temperature oil, its viscosity at an elevated temperature is essentially the same as the SAE 10 base oil; thus combining the useful properties of both oils.

To emphasize the importance of a high V. 1. oil, it is helpful to repeat the above experiments with the same oils in tubes 18 and but with a third oil, which is still of intermediate viscosity but which has a- V. 1. equal to the other two. Clearly, at each of the test temperatures, i. e. 0 F., 70 F. and 212 F., the balls in the three tubes would fall in the same descending order and the effect of a high V. I. would be strikingly apparent.

Having thus described my invention, what I claim as ilOVCi and desire to protect by Letters Patent is as folows:

1. The viscosity demonstration device comprising a sealed tube; a transparent test chamber comprising the major portion of said tube; a reservoir chamber comprising the remainder of said tube; a barrier disposed between said chambers within said tube, having a conduit therein to provide connection therebetween; an extension of said conduit protruding a substantial distance into said reservoir chamber, said extension terminating in a conduit entrance having a diameter substantially less than that of said tube said conduit entrance being centrally located within said reservoir chamber; a quantity of liquid in said tube sufiicient to fill all of said test chamber and enough of the reservoir chamber to assure that the entrance to said conduit, in said reservoir chamher is immersed in said liquid at all times irrespective of the position of said tube; sufhcient liquid-free space in said reservoir chamber to compensate for expansion of said liquid; and an object confined within said test chamber and free to move therein which has a specific gravity substantially greater than said liquid.

2. A viscosity demonstration device comprising a sealed transparent glass tube; a test chamber comprising the major portion of said tube; a reservoir chamber comprising the remainder of said tube; a constricting neck of glass disposed between said chambers within said tube, having a conduit therein to provide connection therebetween, said neck protruding a substantial distance into said reservoir chamber and terminating in a conduit entrance having a diameter substantially less than that of said tube said conduit entrance being centrai- 1y located within said reservoir chamber; a quantity of liquid in said tube sufiicient to completely fill said test chamber and enough of the reservoir chamber to as sure that the entrance to said conduit in said reservoir chamber is immersed in said liquid at all times irrespective of the position of' said tube; sufficient liquid-free space within said reservoirchamber to permit expansion of said liquid; and a metal ball confined within said test chamber and free to move therein which has a specific gravity substantially greater'than said liquid.

3. An apparatus comprising a plurality of the demonstration' devices of claim 1 disposed in substantially parallel relationship; a base support member adapted to receive the lower ends of said devices; an upper support member adapted to receive the upper ends of said devices; and connecting means between said support members adapted to hold said support members and said devices in fixed relationship.

References Citedin the file of this patent UNITED STATES PATENTS 1,427,922 Tiffany Sept. 5, 1922 2,032,197 Blanchard Feb. 25, 1936 2,086,771 Jester July 13, 1937 2,419,658 Rogers Apr. 29, 1947 2,609,682 Eitzen Sept. 9, 1952 

